/* If user disable the ASM, such as avoiding bugs in ASM, donot compile it. */

#if !defined(MD_ST_NO_ASM)

#if defined(__amd64__) || defined(__x86_64__)

/****************************************************************/

/*

* Internal __jmp_buf layout

*/

#define JB_RBX 0

#define JB_RBP 1

#define JB_R12 2 /* Backup IP, https://www.cnblogs.com/Five100Miles/p/8458561.html */

#define JB_R13 3 /* Backup SP, https://www.cnblogs.com/Five100Miles/p/8458561.html */

#define JB_R14 4 /* Backup LR, https://www.cnblogs.com/Five100Miles/p/8458561.html */

#define JB_R15 5 /* Backup PC, https://www.cnblogs.com/Five100Miles/p/8458561.html */

#define JB_RSP 6

#define JB_PC 7

.file "md_darwin.S"

.text

/* _st_md_cxt_save(__jmp_buf env) */ /* The env is rdi, http://blog.chinaunix.net/uid-20157960-id-1974354.html */

.globl __st_md_cxt_save

.align 16

__st_md_cxt_save:

/*

* Save registers.

*/

movq %rbx, (JB_RBX*8)(%rdi) /* Save rbx to env[0], *(int64_t*)(rdi+0)=rbx */

movq %rbp, (JB_RBP*8)(%rdi) /* Save rbp to env[1], *(int64_t*)(rdi+1)=rbp */

movq %r12, (JB_R12*8)(%rdi) /* Save r12 to env[2], *(int64_t*)(rdi+2)=r12 */

movq %r13, (JB_R13*8)(%rdi) /* Save r13 to env[3], *(int64_t*)(rdi+3)=r13 */

movq %r14, (JB_R14*8)(%rdi) /* Save r14 to env[4], *(int64_t*)(rdi+4)=r14 */

movq %r15, (JB_R15*8)(%rdi) /* Save r15 to env[5], *(int64_t*)(rdi+5)=r15 */

/* Save SP */

leaq 8(%rsp), %rdx /* Save *(int64_t*)(rsp+8) to rdx, https://my.oschina.net/guonaihong/blog/508907 */

movq %rdx, (JB_RSP*8)(%rdi) /* Save rdx(rsp) to env[6], *(int64_t*)(rdi+6)=rdx */

/* Save PC we are returning to */

movq (%rsp), %rax /* Save PC(parent function address) %(rsp) to rax */

movq %rax, (JB_PC*8)(%rdi) /* Save rax(PC) to env[7], *(int64_t*)(rdi+7)=rax */

xorq %rax, %rax /* Reset rax to 0 */

ret

/****************************************************************/

/* _st_md_cxt_restore(__jmp_buf env, int val) */ /* The env is rdi, val is esi/rsi, http://blog.chinaunix.net/uid-20157960-id-1974354.html */

.globl __st_md_cxt_restore

.align 16

__st_md_cxt_restore:

/*

* Restore registers.

*/

movq (JB_RBX*8)(%rdi), %rbx /* Load rbx from env[0] */

movq (JB_RBP*8)(%rdi), %rbp /* Load rbp from env[1] */

movq (JB_R12*8)(%rdi), %r12 /* Load r12 from env[2] */

movq (JB_R13*8)(%rdi), %r13 /* Load r13 from env[3] */

movq (JB_R14*8)(%rdi), %r14 /* Load r14 from env[4] */

movq (JB_R15*8)(%rdi), %r15 /* Load r15 from env[5] */

/* Set return value */ /* The esi is param1 val, the eax is return value */

test %esi, %esi /* if (!val) { */

mov $01, %eax /* val=1; */

cmove %eax, %esi /* } */

mov %esi, %eax /* return val; */

movq (JB_PC*8)(%rdi), %rdx /* Load rdx(PC) from env[7] */

movq (JB_RSP*8)(%rdi), %rsp /* Load rsp from env[6] */

/* Jump to saved PC */

jmpq *%rdx /* Jump to rdx(PC) */

/****************************************************************/

#endif

#endif